takoyaki and otonomiyake for starters.
mmmmmm - go to dotonbori/shinsaibashi/namba probably the most lively parts of Osaka for streetlife
although i had great kushiage (like tempura but breaded instead of batter) in Tennoji - there's also a weird yakuza controlled redlight area around there and Japan's largest slum area called Nishinari
The view from Umeday Sky building by Hiroshi Hara is pretty amazing, actually that building is just incredible -
http://www.google.co.uk/imgres?imgu...Kr_T6f4JYeciQeso4SYCA&ved=0CG0Q9QEwAg&dur=975
but one of osaka's greatest virtues is its transport and the fact that you can leave it fairly easily - there's so much to see in the surrounding area if you want to escape big city. Thinking specifically of spending days touring sake breweries in Kobe (nada), visiting Nara, Asuka, etc..
Kyoto is only 30-40mins away by train.
How long you in osaka for?